CVID Diagnosis and Treatment Guidelines

Diagnostic Criteria

The American Academy of Allergy, Asthma, and Immunology recommends that patients with CVID should have impaired antibody responses to pneumococcal polysaccharide vaccine, which is not the case for this patient who demonstrated a good response to pneumococcal vaccination in 2021 and still maintains protective levels in 11/23 serotypes as of November 2023 1, 2
The Journal of Allergy and Clinical Immunology suggests that patients with CVID typically have recurrent bacterial respiratory infections, which is not consistent with this patient's clinical picture of prosthetic joint infection with chronic suppression 3

The FDA recommends a standard conversion from IVIG to subcutaneous immunoglobulin, with an initial weekly dose = (Previous IGIV dose in grams × 1.30) ÷ Number of weeks between IGIV doses [@FDA Label@, 4]
The typical monthly IVIG dose is 400-600 mg/kg/month, which translates to approximately 100-150 mg/kg/week for subcutaneous administration, with a maximum dose in literature of up to 1.2 g/kg/month for patients with bronchiectasis 1, 4

The FDA warns of severe volume overload, risk of thrombotic events, renal dysfunction, and hemolysis associated with high-dose immunoglobulin therapy [@FDA Label@, 2, 3]

The Journal of Allergy and Clinical Immunology recommends continued monitoring of IgG levels, IgA, and IgM every 6-12 months to assess for evolution to true CVID, as well as repeat pneumococcal antibody titers if there is clinical deterioration 1, 3
Optimize management of prosthetic joint infection and allergic rhinosinusitis with appropriate antibiotic suppression and allergy treatment, respectively 3